Hydropower is the most important renewable energy source to date, providing over 72% of all renewable electricity globally. Yet, only limited information is available on the global potential supply of hydropower and the associated costs. Here we provide a high-resolution assessment of the technical and economic potential of hydropower at a near-global scale. Using 15”×15” discharge and 3”×3” digital elevation maps, we built virtual hydropower installations at >3.8 million sites across the globe and calculated their potential using cost optimization methods.

This way we identified over 60,000 suitable sites, which together represent a remaining global potential of 9.49 PWh yr−1 below US$0.50 kWh−1. The largest remaining potential is found in Asia Pacific (39%), South America (25%) and Africa (24%), of which a large part can be produced at low cost (<US$0.10 kWh−1). In an ecological scenario, this potential is reduced to 5.67 PWh yr−1.